Bearing surface



Oct. 23, 1951 A. F. FOLZ BEARING SURFACE Filed Jan. 16, 1946 ARTHUR F.FQLZ Patented Oct. 23, 1951 UNITED STATES PATENT OFFICE (Granted underthe act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4Claims.

This invention relates to an improvement in bearing surfaces, and, inparticular, to a grooved bearing surface adapted to receive and dispensea liquid lubricant between two relatively moving frictionally engagedparts such as a piston 4 reciprocating within a cylinder or a journalrotating within its supporting bearing.

Heretofore, various and sundry difficulties have been experienced inmaintaining bearings within safe operating temperatures by reason of thefact that the relative speeds of the frictionally engaged Darts havebeen so high that the supply of lubricant maintained therebetween isinadequate to provide proper lubrication. Particularly, when a piston iscaused to reciprocate within its cylinder from the standing to therunning condition, the initial supply of lubricant is usually of aninsufllcient quantity to avoid direct metal to metal contact ofreciprocating surfaces. This is true where the reciprocating parts havebeen stationary for a considerable length of time, thus permitting theoil to drain into the sump or the like, causing the surfaces of thepiston and cylinder to become dry.

It is one object of this invention, therefore, to provide a hearingwhich will insure proper lubrication between relatively moving bearingparts under all conditions of operation.

Another object of the invention is to provide a low friction,economically operable bearing which is relatively simple to manufactureand assemble.

It is a further object of this invention to provide a bearing surfacehaving long wearing qualities, thus insuring long life and relativelylittle servicing.

These objects, as well as the various other novel features andadvantages ofithis invention, will become apparent from a reading of thespecification and accompanying drawings of which:

Figure 1 is a cross-sectional elevational view of a journal bearing or asectional-elevational view of a. part of an internal combustion enginecylinder embodying the features of this inven tion, showing a pluralityof liquid lubricant receiving and dispensing grooves extending acrossthe face thereof;

Figure 2 is a sectional view taken at 2-2 of Figure 1, in which is shownthe cross-sectional shape of the grooves formed in the bearing face;

Figure 3 is an enlarged view similar to that of Figure 2 but in which isshown a bearing surface, grooved in accordance with this invention. and

has been added by any well-known deposition process; and

Figure 4 is an enlarged plan view of a small portion of the bearingsurface of Figure 1, indicating the relative spacing between the groovesand the actual load-supporting surface of the bearing.

With reference to Figures 1, 2 and 3, the bearing surface disclosedtherein comprises a base ll, into which a plurality of threads orgrooves l2 have been cut by means of a thread grinding or thread cuttingtool, and to which a coating l3 of chromium or the like has been appliedby means of an electrolytic process.

with respect to the threads or grooves 12, it has been found thatdepending upon the type of service to which the bearing manufactured inaccordance with this invention is to be subjected, the pitch thereof maybe selected from within the range of about 20 to threads per inch.Although the depth and width of groove may be varied to suit variousconditions of operation to which the hearing will ultimately besubjected, it has been determined that a width of groove ofapproximately .005 of an inch having relatively vertical side portionsI4 and a depth of approximately .004 of an inch will give verysatisfactory results. These dimensions are obviously such as producecapillarity in the grooves when liquids are brought into contact withthe bearing surface whereby the liquid is il letained on the surfaceover substantial time pcods.

By reason of the application of the electrolyticalLv deposited metalcoating I3 in accordance with Figure 3, the depth of thread or groove I2 will be relatively deeper than it was prior to coating inasmuch as themetal supplied by the electrolytic process is much more freely receivedon the bearing surface which is to support the load than it is at thesides It or bottom 15 of the grooves. Thus, not only does the coatingprovide a much better wear resistant surface, but by having a relativelydeeper liquid lubricant receiving and dispensing groove, any wear whichmay take place will have very little influence upon the effect of threador groove depth.

Although, as illustrated, an electrolytically deposited chromium coatingon the surface of the hearing has, by experiment, shown marked im-.-provement over conventional chromium coated bearings, by other tests, ithas been determined that a highly polished bearing surfaceconsistelectrolytic to which a coating of metal, such as chromium, 66ing of the base metal into which a plurality of liquid lubricantreceiving and dispensing threads or grooves have been formed will givevery satisfactory results under certain running conditractlve force onlubricating oil, and a coating of hard bearing metal on said surface.said coating being thicker on the bearing faces of the tions. Not onlyis frictional wear reduced to a minimum through use of the bearingsurface I embodying the features of the invention disclosed herein, butmuch better operation of relatively moving contacting elements isinsured.

It will be understood that the above description and accompanyingdrawings comprehend only the general and preferred embodiment of thisinvention and that various changes in construction and proportion aswell as arrangement of the grooves or depressions may be made within thescope of the appended claims without sacrificing any of the advantagesof the invention.

i surface lands than in said grooves.

d. A cylinder for an internal combustion engine comprising a cylindersidewall provided with a relatively smooth surface toward the interiorof said cylinder, thread grooves helically cut in said surface at apitch within the range of from '20 to 100 threads per inch to dividesaid surface into lands and grooves, said grooves having v,awicilth ofabout 0.005 inch and a depth of about 0.004. inch and. a coating ofelectrolytically deposited chromium on said surface and in said Theinvention described herein may be manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed is:

1. A hearing comprising a load supporting base having a uniformlyone-way grooved bearing surface, and a coating of bearing metal on saidsurface, the grooves of said surface having a width of approximately0.005 inch and a depth of approximately 0.004 inch.

2. A hearing comprising a load supporting base having a grooved bearingsurface and an electrolytic coating of bearing metal on said sur face,said grooves being of such dimensions as to width and depth as to exerta capillary attractive force on lubricating oil.

3. A bearing comprising aload supporting base having a finely groovedbearing surface wherein each groove is of such dimensions with respectto width and depth as to exert a capillary atgrooves, said. coatingbeing thicker on the surface of said lands than in said grooves and saidcoated grooves characterized, by reason of their width and depthdimensions, by the ability to capillarily attract and retain lubricatingoil therein,

ARTHUR F. FOLZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

